gscd.c

还有没有人研究过cdrom 的驱动源码啊

#define GSCD_VERSION "0.4a Oliver Raupach <[e-mail]>"

/*
	linux/drivers/block/gscd.c - GoldStar R420 CDROM driver

        Copyright (C) 1995  Oliver Raupach <[e-mail]>
        based upon pre-works by   Eberhard Moenkeberg <[e-mail]>
        

        For all kind of other information about the GoldStar CDROM
        and this Linux device driver I installed a WWW-URL:
        http://linux.rz.fh-hannover.de/~raupach        


             If you are the editor of a Linux CD, you should
             enable gscd.c within your boot floppy kernel and
             send me one of your CDs for free.


        --------------------------------------------------------------------
	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2, or (at your option)
	any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	
	--------------------------------------------------------------------
	
	9 November 1999 -- Make kernel-parameter implementation work with 2.3.x 
	                   Removed init_module & cleanup_module in favor of 
		   	   module_init & module_exit.
			   Torben Mathiasen <[e-mail]>

*/

/* These settings are for various debug-level. Leave they untouched ... */
#define  NO_GSCD_DEBUG
#define  NO_IOCTL_DEBUG
#define  NO_MODULE_DEBUG
#define  NO_FUTURE_WORK
/*------------------------*/

#include <linux/module.h>

#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/kernel.h>
#include <linux/cdrom.h>
#include <linux/ioport.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/devfs_fs_kernel.h>

#include <asm/system.h>
#include <asm/io.h>
#include <asm/uaccess.h>

#define MAJOR_NR GOLDSTAR_CDROM_MAJOR
#include <linux/blk.h>
#define gscd_port gscd		/* for compatible parameter passing with "insmod" */
#include "gscd.h"

static int gscd_blocksizes[1] = { 512 };

static int gscdPresent = 0;

static unsigned char gscd_buf[2048];	/* buffer for block size conversion */
static int gscd_bn = -1;
static short gscd_port = GSCD_BASE_ADDR;
MODULE_PARM(gscd, "h");

/* Kommt spaeter vielleicht noch mal dran ...
 *    static DECLARE_WAIT_QUEUE_HEAD(gscd_waitq);
 */

static void gscd_transfer(void);
static void gscd_read_cmd(void);
static void gscd_hsg2msf(long hsg, struct msf *msf);
static void gscd_bin2bcd(unsigned char *p);

/* Schnittstellen zum Kern/FS */

static void do_gscd_request(request_queue_t *);
static void __do_gscd_request(unsigned long dummy);
static int gscd_ioctl(struct inode *, struct file *, unsigned int,
		      unsigned long);
static int gscd_open(struct inode *, struct file *);
static int gscd_release(struct inode *, struct file *);
static int check_gscd_med_chg(kdev_t);

/*      GoldStar Funktionen    */

static void cc_Reset(void);
static int wait_drv_ready(void);
static int find_drives(void);
static void cmd_out(int, char *, char *, int);
static void cmd_status(void);
static void cc_Ident(char *);
static void cc_SetSpeed(void);
static void init_cd_drive(int);

static int get_status(void);
static void clear_Audio(void);
static void cc_invalidate(void);

/* some things for the next version */
#ifdef FUTURE_WORK
static void update_state(void);
static long gscd_msf2hsg(struct msf *mp);
static int gscd_bcd2bin(unsigned char bcd);
#endif

/*    common GoldStar Initialization    */

static int my_gscd_init(void);


/*      lo-level cmd-Funktionen    */

static void cmd_info_in(char *, int);
static void cmd_end(void);
static void cmd_read_b(char *, int, int);
static void cmd_read_w(char *, int, int);
static int cmd_unit_alive(void);
static void cmd_write_cmd(char *);


/*      GoldStar Variablen     */

static int curr_drv_state;
static int drv_states[] = { 0, 0, 0, 0, 0, 0, 0, 0 };
static int drv_mode;
static int disk_state;
static int speed;
static int ndrives;

static unsigned char drv_num_read;
static unsigned char f_dsk_valid;
static unsigned char current_drive;
static unsigned char f_drv_ok;


static char f_AudioPlay;
static char f_AudioPause;
static int AudioStart_m;
static int AudioStart_f;
static int AudioEnd_m;
static int AudioEnd_f;

static struct timer_list gscd_timer;

static struct block_device_operations gscd_fops = {
	owner:THIS_MODULE,
	open:gscd_open,
	release:gscd_release,
	ioctl:gscd_ioctl,
	check_media_change:check_gscd_med_chg,
};

/* 
 * Checking if the media has been changed
 * (not yet implemented)
 */
static int check_gscd_med_chg(kdev_t full_dev)
{
	int target;


	target = MINOR(full_dev);

	if (target > 0) {
		printk
		    ("GSCD: GoldStar CD-ROM request error: invalid device.\n");
		return 0;
	}
#ifdef GSCD_DEBUG
	printk("gscd: check_med_change\n");
#endif

	return 0;
}


#ifndef MODULE
/* Using new interface for kernel-parameters */

static int __init gscd_setup(char *str)
{
	int ints[2];
	(void) get_options(str, ARRAY_SIZE(ints), ints);

	if (ints[0] > 0) {
		gscd_port = ints[1];
	}
	return 1;
}

__setup("gscd=", gscd_setup);

#endif

static int gscd_ioctl(struct inode *ip, struct file *fp, unsigned int cmd,
		      unsigned long arg)
{
	unsigned char to_do[10];
	unsigned char dummy;


	switch (cmd) {
	case CDROMSTART:	/* Spin up the drive */
		/* Don't think we can do this.  Even if we could,
		 * I think the drive times out and stops after a while
		 * anyway.  For now, ignore it.
		 */
		return 0;

	case CDROMRESUME:	/* keine Ahnung was das ist */
		return 0;


	case CDROMEJECT:
		cmd_status();
		to_do[0] = CMD_TRAY_CTL;
		cmd_out(TYPE_INFO, (char *) &to_do, (char *) &dummy, 0);

		return 0;

	default:
		return -EINVAL;
	}

}


/*
 * Take care of the different block sizes between cdrom and Linux.
 * When Linux gets variable block sizes this will probably go away.
 */

static void gscd_transfer(void)
{
	long offs;

	while (CURRENT->nr_sectors > 0 && gscd_bn == CURRENT->sector / 4) {
		offs = (CURRENT->sector & 3) * 512;
		memcpy(CURRENT->buffer, gscd_buf + offs, 512);
		CURRENT->nr_sectors--;
		CURRENT->sector++;
		CURRENT->buffer += 512;
	}
}


/*
 * I/O request routine called from Linux kernel.
 */

static void do_gscd_request(request_queue_t * q)
{
	__do_gscd_request(0);
}

static void __do_gscd_request(unsigned long dummy)
{
	unsigned int block, dev;
	unsigned int nsect;

      repeat:
	if (QUEUE_EMPTY || CURRENT->rq_status == RQ_INACTIVE)
		goto out;
	INIT_REQUEST;
	dev = MINOR(CURRENT->rq_dev);
	block = CURRENT->sector;
	nsect = CURRENT->nr_sectors;

	if (QUEUE_EMPTY || CURRENT->sector == -1)
		goto out;

	if (CURRENT->cmd != READ) {
		printk("GSCD: bad cmd %d\n", CURRENT->cmd);
		end_request(0);
		goto repeat;
	}

	if (MINOR(CURRENT->rq_dev) != 0) {
		printk("GSCD: this version supports only one device\n");
		end_request(0);
		goto repeat;
	}

	gscd_transfer();

	/* if we satisfied the request from the buffer, we're done. */

	if (CURRENT->nr_sectors == 0) {
		end_request(1);
		goto repeat;
	}
#ifdef GSCD_DEBUG
	printk("GSCD: dev %d, block %d, nsect %d\n", dev, block, nsect);
#endif

	gscd_read_cmd();
      out:
	return;
}



/*
 * Check the result of the set-mode command.  On success, send the
 * read-data command.
 */

static void gscd_read_cmd(void)
{
	long block;
	struct gscd_Play_msf gscdcmd;
	char cmd[] = { CMD_READ, 0x80, 0, 0, 0, 0, 1 };	/* cmd mode M-S-F secth sectl */



	cmd_status();
	if (disk_state & (ST_NO_DISK | ST_DOOR_OPEN)) {
		printk("GSCD: no disk or door open\n");
		end_request(0);
	} else {
		if (disk_state & ST_INVALID) {
			printk("GSCD: disk invalid\n");
			end_request(0);
		} else {
			gscd_bn = -1;	/* purge our buffer */
			block = CURRENT->sector / 4;
			gscd_hsg2msf(block, &gscdcmd.start);	/* cvt to msf format */

			cmd[2] = gscdcmd.start.min;
			cmd[3] = gscdcmd.start.sec;
			cmd[4] = gscdcmd.start.frame;

#ifdef GSCD_DEBUG
			printk("GSCD: read msf %d:%d:%d\n", cmd[2], cmd[3],
			       cmd[4]);
#endif
			cmd_out(TYPE_DATA, (char *) &cmd,
				(char *) &gscd_buf[0], 1);

			gscd_bn = CURRENT->sector / 4;
			gscd_transfer();
			end_request(1);
		}
	}
	SET_TIMER(__do_gscd_request, 1);
}


/*
 * Open the device special file.  Check that a disk is in.
 */

static int gscd_open(struct inode *ip, struct file *fp)
{
	int st;

#ifdef GSCD_DEBUG
	printk("GSCD: open\n");
#endif

	if (gscdPresent == 0)
		return -ENXIO;	/* no hardware */

	get_status();
	st = disk_state & (ST_NO_DISK | ST_DOOR_OPEN);
	if (st) {
		printk("GSCD: no disk or door open\n");
		return -ENXIO;
	}

/*	if (updateToc() < 0)
		return -EIO;
*/

	return 0;
}


/*
 * On close, we flush all gscd blocks from the buffer cache.
 */

static int gscd_release(struct inode *inode, struct file *file)
{

#ifdef GSCD_DEBUG
	printk("GSCD: release\n");
#endif

	gscd_bn = -1;

	return 0;
}


int get_status(void)
{
	int status;

	cmd_status();
	status = disk_state & (ST_x08 | ST_x04 | ST_INVALID | ST_x01);

	if (status == (ST_x08 | ST_x04 | ST_INVALID | ST_x01)) {
		cc_invalidate();
		return 1;
	} else {
		return 0;
	}
}


void cc_invalidate(void)
{
	drv_num_read = 0xFF;
	f_dsk_valid = 0xFF;
	current_drive = 0xFF;
	f_drv_ok = 0xFF;

	clear_Audio();

}

void clear_Audio(void)
{

	f_AudioPlay = 0;
	f_AudioPause = 0;
	AudioStart_m = 0;
	AudioStart_f = 0;
	AudioEnd_m = 0;
	AudioEnd_f = 0;

}

/*
 *   waiting ?  
 */

int wait_drv_ready(void)
{
	int found, read;

	do {
		found = inb(GSCDPORT(0));
		found &= 0x0f;
		read = inb(GSCDPORT(0));
		read &= 0x0f;
	} while (read != found);

#ifdef GSCD_DEBUG
	printk("Wait for: %d\n", read);
#endif

	return read;
}

void cc_Ident(char *respons)
{
	char to_do[] = { CMD_IDENT, 0, 0 };

	cmd_out(TYPE_INFO, (char *) &to_do, (char *) respons, (int) 0x1E);

}

void cc_SetSpeed(void)
{
	char to_do[] = { CMD_SETSPEED, 0, 0 };
	char dummy;

	if (speed > 0) {
		to_do[1] = speed & 0x0F;
		cmd_out(TYPE_INFO, (char *) &to_do, (char *) &dummy, 0);
	}
}


void cc_Reset(void)
{
	char to_do[] = { CMD_RESET, 0 };
	char dummy;

	cmd_out(TYPE_INFO, (char *) &to_do, (char *) &dummy, 0);
}



void cmd_status(void)
{
	char to_do[] = { CMD_STATUS, 0 };
	char dummy;

	cmd_out(TYPE_INFO, (char *) &to_do, (char *) &dummy, 0);

#ifdef GSCD_DEBUG
	printk("GSCD: Status: %d\n", disk_state);
#endif

}

void cmd_out(int cmd_type, char *cmd, char *respo_buf, int respo_count)
{
	int result;


	result = wait_drv_ready();
	if (result != drv_mode) {
		unsigned long test_loops = 0xFFFF;
		int i, dummy;

		outb(curr_drv_state, GSCDPORT(0));

		/* LOCLOOP_170 */
		do {
			result = wait_drv_ready();
			test_loops--;
		} while ((result != drv_mode) && (test_loops > 0));

		if (result != drv_mode) {